Billions of kg of CO2 could be saved by scrapping DVDs, research suggests

A trip down to the local DVD store has slowly become a thing of the past thanks to the rise of video streaming services, which allow viewers to indulge in back-to-back episodes of hit TV series like House of Cards and Breaking Bad at the click of a button.

Now, a new study has shown that streaming can be much better for the environment, requiring less energy and emitting less carbon dioxide (CO2), than some traditional methods of DVD renting, buying and viewing.

The researchers, who have published their study today, 29 May, in IOP Publishing's journal Environmental Research Letters, cite modern devices such as laptops and tablets as the reason for this improvement, as they are much more efficient than older, energy-sapping DVD players.

Furthermore, the driving that is required to go and buy, or rent, DVDs makes this method much more energy- and carbon-intensive.

A significant proportion of the energy consumption and carbon emissions for streaming comes from the transmission of data, which increases drastically when more complex, high-definition content is streamed.

In their study, the researchers, from Lawrence Berkley National Laboratory and Northwestern University, estimated that if all DVD viewing in the US was shifted to streaming services in 2011, around 2 billion kg of CO2 emissions could have been avoided and around 30 petajoules (PJ) of energy saved--the equivalent of the amount of electricity needed to meet the demands of 200,000 US households.

They estimated that in 2011, 192 PJ of energy was used, and 10.4 billion kg of CO2 emitted, for all methods of DVD consumption and streaming in the US.

From this, they calculated that one hour of video streaming requires 7.9 megajoules (MJ) of energy, compared to as much as 12 MJ for traditional DVD viewing, and emits 0.4 kg of CO2, compared to as much as 0.71 kg of CO2 for DVD viewing.

To arrive at their results, the researchers compared video streaming with four different types of DVD consumerism: DVDs that are rented from online mailers; DVDs that are rented from a store; DVDs that are purchased online; and DVDs that are bought from a store.

Video streaming was limited to TV and movies and did not include shorter videos that are streamed online through YouTube etc.

They found that video streaming and the online rental of DVDs required similar amounts of energy; however, the renting and purchasing of DVDs from a store were much more energy intensive, due to the impact of driving.

Lead author of the research Arman Shehabi, from Lawrence Berkley National Laboratory, said: "It's a modern-day equivalent of the debate about which is more environmentally sound--the disposable or the cloth diaper.

"Our study suggests that equipment designers and policy makers should focus on improving the efficiency of end-user devices and network transmission energy to curb the energy use from future increases in video streaming.

"Such efficiency improvements will be particularly important in the near future, when society is expected to consume far greater quantities of streaming video content compared to today."

###

Fast Facts:

An estimated 1.2 billion DVDs were purchased in the US in 2011

An estimated 17.2 billion hours of DVDs were viewed in 2011 in the US

An estimated 3.2 billion hours of movies and television programmes were streamed in the US in 2011

The percentages of total video streaming viewing time attributable to computers, televisions, and mobile devices in 2011 are estimated at 20%, 77%, and 3%, respectively

1. For further information, a full draft of the journal paper or contact with one of the researchers, contact IOP Press Officer, Michael Bishop: Tel: 0117 930 1032 E-mail: michael.bishop@iop.org For more information on how to use the embargoed material above, please refer to our embargo policy.

IOP Publishing Journalist Area

2. The IOP Publishing Journalist Area gives journalists access to embargoed press releases, advanced copies of papers, supplementary images and videos. In addition to this, a weekly news digest is uploaded into the Journalist Area every Friday, highlighting a selection of newsworthy papers set to be published in the following week. Login details also give free access to IOPscience, IOP Publishing's journal platform. To apply for a free subscription to this service, please email Michael Bishop, IOP Press Officer, michael.bishop@iop.org, with your name, organisation, address and a preferred username.

The energy and greenhouse gas implications of internet video streaming in the United States

3. The published version of the paper 'The energy and greenhouse has implications of internet video streaming in the United States' (Arman Shehabi et al 2014 Environ. Res. Lett. 9 054007) will be freely available online from Thursday 29 May. It will be available at http://iopscience.iop.org/1748-9326/9/5/054007/article.

Environmental Research Letters

4. Environmental Research Letters is an open access journal that covers all of environmental science, providing a coherent and integrated approach including research articles, perspectives and editorials.

IOP Publishing

5. IOP Publishing provides a range of journals, magazines, websites and services that enable researchers and research organisations to reach the widest possible audience for their research. We combine the culture of a learned society with global reach and highly efficient and effective publishing systems and processes. With offices in the UK, US, Germany, China and Japan, and staff in many other locations including Mexico and Russia, we serve researchers in the physical and related sciences in all parts of the world. IOP Publishing is a wholly owned subsidiary of the Institute of Physics. The Institute is a leading scientific society promoting physics and bringing physicists together for the benefit of all. Any profits generated by IOP Publishing are used by the Institute to support science and scientists in both the developed and developing world. Go to ioppublishing.org.

Access to Research

6. Access to Research is an initiative through which the UK public can gain free, walk-in access to a wide range of academic articles and research at their local library. This article is freely available through this initiative. For more information, go to http://www.accesstoresearch.org.uk

The Institute of Physics

6. The Institute of Physics is a leading scientific society. We are a charitable organisation with a worldwide membership of more than 50,000, working together to advance physics education, research and application.

We engage with policymakers and the general public to develop awareness and understanding of the value of physics and, through IOP Publishing, we are world leaders in professional scientific communications.

In September 2013, we launched our first fundraising campaign. Our campaign, Opportunity Physics, offers you the chance to support the work that we do.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.